Final answer:
Alicia returned Ricardo's Saint Bernard without knowledge of a reward being offered. Under contract law, a reward constitutes a unilateral contract that requires the offeree's knowledge of the reward before completing the requested action, so Alicia is typically not entitled to the reward.
Step-by-step explanation:
The subject of the question pertains to contract law, specifically about the entitlement to a reward for performing an action. In the scenario described, Ricardo posts a sign offering a reward for the return of his Saint Bernard, which Alicia returns without knowledge of the reward. Under typical contract law principles, a reward is a form of unilateral contract, where the offeror promises to pay after the performance of an act.
For the offeree to be entitled to the reward, they must have knowledge of the reward prior to completing the requested action. Since Alicia did not have knowledge of the reward before returning the dog, she is generally not entitled to the reward upon completion of the act.